Affiliation:
1. Center for Agricultural Molecular Biology, Rutgers, State University of New Jersey, New Brunswick 08903.
Abstract
T1, a dentrifying bacterium originally isolated for its ability to grow on toluene, can also metabolize 4-hydroxybenzoate and other aromatic compounds under denitrifying conditions. A cosmid clone carrying the three genes that code for the 4-chlorobenzoate dehalogenase enzyme complex isolated from the aerobic bacterium Pseudomonas sp. strain CBS3 was successfully conjugated into strain T1. The cloned enzyme complex catalyzes the hydrolytic dechlorination of 4-chlorobenzoate to 4-hydroxybenzoate. Since molecular oxygen is not required for the dehalogenation reaction, the transconjugate strain of T1 (T1-pUK45-10C) was able to grow on 4-chlorobenzoate in the absence of O2 under denitrifying conditions. 4-Chlorobenzoate was dehalogenated to 4-hydroxybenzoate, which was then further metabolized by strain T1. The dehalogenation and metabolism of 4-chlorobenzoate were nitrate dependent and were coupled to the production of nitrite and nitrogen gas. 4-Bromobenzoate was also degraded by this strain, while 4-iodobenzoate was not. Additionally, when T1-pUK45-10C was presented with a mixture of 4-chlorobenzoate and toluene, simultaneous degradation of the compounds was observed. These results illustrate that dechlorination and degradation of aromatic xenobiotics can be mediated by a pure culture in the absence of oxygen. Furthermore, it is possible to expand the range of xenobiotic substrates degradable by an organism, and it is possible that concurrent metabolism of these substrates can occur.
Publisher
American Society for Microbiology
Subject
Ecology,Applied Microbiology and Biotechnology,Food Science,Biotechnology
Cited by
42 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献